Piracy and illicit copying of film prints erode the revenue stream in the film industry, and also violate the intellectual property rights established for the film media.
Piracy issues in connection with motion pictures and their distribution are well known. Once a film distributor distributes prints of a motion picture film to exhibitors for theatrical exhibition, a certain degree of control over the product is lost. In the regular course of exhibiting the film, a customer in the theater may surreptitiously record the film using, for example, a hand held camcorder or other recording device. At a more sophisticated level, a person seeking to obtain an illegal copy of a film print may gain access to a theater projection booth in collusion with an employee of the exhibitor and make a copy of the film after hours in a relatively controlled environment. In such an environment, the quality of the audio can be greatly improved because the audio tracks can be fed from the projection equipment directly to the recording device. A tripod can even be used to ensure a clearer and steadier picture quality. Alternatively, the print itself may be scanned to create a video master. One way or another, the illicit copy can be made.
Film prints for distribution to exhibition theatres are presently marked in a manner that is visible in illicit copies of the content. Forensic marking is taught is exemplary, patent documents including: U.S. Pat. No. 7,206,409 issued to Antonellis et al., entitled “Motion Picture Anti-Piracy Coding”; and U.S. Patent Application Publication No. 2009/0123022 for Derrenberger et al., entitled “Digital Cinema Projector Watermarking System and Method”. These references are expressly incorporated herein by reference in their entirety. Both references show examples of forensic marks applied to non-stereoscopic media content in film and digital cinema forms.
While forensic marking has been applied successfully to non-stereoscopic content (2D), it appears that few, if any, techniques have been developed for stereoscopic content in which stereoscopic 3D motion picture images are projected via dual lens systems using either a single projector or a pair of projectors. Forensic marking techniques, such as those proffered for protecting non-stereoscopic content, have not been proposed in standards organizations or the like for protecting stereoscopic 3D content in a similar manner. Non-stereoscopic forensic marking techniques have not been successfully applied to stereoscopic 3D motion pictures projected from dual lens projection systems. It is expected that the application of marking techniques similar to those in the cited references, when applied to stereoscopic 3D motion picture presentations in the manner shown below, would result in the forensic marks losing at least some amount of their effectiveness and usefulness because of possible corruption and degraded detectability.
The known prior methods and apparatus appear to lack any suitable anti-piracy measures involving forensic marking of stereoscopic 3D media, whether film-based or digital cinema.